An exterior storage device, also referred to as auxiliary storage and secondary storage, is a an equipment that contains all the addressable data storage that is no inside a computer"s main storage or memory. An outside storage device can it is in removable or non-removable, short-lived or permanent, and easily accessible over a wired or wireless network.

You are watching: Remote storage services accessed via the internet are often referred to as cloud storage.

External storage enables users to store data separately from a computer"s key or primary storage and also memory at a reasonably low cost. It rises storage volume without having to open up a system.

External storage is frequently used to store details that"s accessed less typically by applications running on a desktop, laptop, server or cell phone device, such as an Android or iOS smartphone or tablet.

For PCs, an external storage an equipment often consists of stationary or portable tough disk drives (HDDs), or solid-state drives (SSDs) attached via a USB or FireWire connection, or wirelessly.

For enterprises, an external storage machine can offer as main storage associated to servers v Ethernet or Fibre Channel switches, or as secondary storage for backup and also archiving purposes. Exterior storage uses HDD, all-flash and also hybrid storage arrays for block-based, file-based or thing storage, or a mix that these three protocols recognized as merged storage. Storage area networks (SANs) because that block-level storage and network-attached warehouse (NAS) tools for file-based storage are instances of exterior storage.

Another typical use case for an exterior storage device is to transfer data between on-site and also off-site computer system systems.

When moving huge amounts that data to the cloud, companies will regularly use exterior storage devices in a practice well-known as cloud seeding. Since moving tens of terabytes of data end a network deserve to take hrs or days, customers location their data ~ above an external storage device and climate send the device to their preferred provider come copy locally. After the early seeding, only changed data will certainly move across the network to the cloud for backup, archiving or catastrophe recovery (DR) purposes.

Types of external storage devices and also the pros and cons the each

External storage gadgets come in countless forms, both removable and non-removable. A common characteristic is the they room nonvolatile and data is stored exterior of the computer or multiple computer systems -- server, desktop, mobile and also so top top -- reading data from and also writing data come them.

external HDD

Common portable and also fixed exterior storage tools include HDDs, a form of magnetic storage, and also SSDs, which usage flash modern technology with capacities beginning in the gigabyte selection to 10 terabytes (TB) and higher.

While the price the flash has fallen, comparable HDDs are still considerably cheaper to buy. Due to the fact that there room no relocating parts to flash SSDs, castle are substantially faster and more durable than HDDs. External hard disks and also flash drives are often used because that data protection, backup, DR and long-term retention purposes.

Intel"s 3D XPoint-based Optane solid-state journey

Tape is another type of removable Magnetic storage. The most prevalent tape format today is straight Tape-Open (LTO). LTO specifications were occurred by Hewlett-Packard, IBM and Seagate modern technology in 1997.

The very first generation the LTO, LTO-1, sustained a capacity of 200 GB compressed in ~ a preferably compressed transfer price of 40 megabytes per second (MBps). The recent generation, LTO-8, supports 32 TB at 1,180 MBps. The roadmap because that LTO-9 calls because that 62.6 TB in ~ 1,770 MBps.

linear Tape-Open 8 (LTO-8) ice drive and also media

Because the price that HDDs has actually fallen when capacities have actually increased, tough disks have largely changed tape as the key medium because that backup. However, ice cream is still commonly used because that archiving and DR since of that is portability and capability to hold an ext data per cartridge.

Enterprises typically ago up main data to HDDs as one an additional storage tier, and also then offload data to tape for long-term archiving and DR warehouse tiers, often using tape libraries with automated cartridge handling.

an automated ice library

Another type of external storage maker is optical storage, i beg your pardon writes and also reads digital content making use of a laser. This group includes removable media, such as compact discs (CDs) in layouts such together CD-ROM, CD-R and also CD-RW, which room basically defunct for computer system storage purposes; DVDs v a volume of 4.7 GB single- and also 9.4 GB double-sided; and also Blu-ray, with a capacity of 5 GB single-layer and also 50 GB dual-layer.

Optical media formats

While an ext durable than tape, optical storage is slow than tough disk. Optical libraries, or jukeboxes, greatly broaden the energy of optical storage once it concerns long-term archiving and DR.

Small and also removable USB flash drives and media cards because that smartphones, tablets, cameras and so on, are instances of portable and removable exterior storage gadgets in a small form factor (SFF).

USB flash drive photo

While not a machine per se, the cloud is another form of external storage supplied by companies -- for backend together a service, disaster recovery as a service, infrastructure as a service and also storage as a company -- and individuals.

Among the many common and useful varieties of exterior cloud warehouse are file sharing services, such together Box and also Dropbox.

External warehouse vs. Internal storage

Nonvolatile exterior storage is generally lower performing and also less costly 보다 volatile interior storage -- also known as primary or key storage -- i m sorry holds data the is frequently accessed by a computer"s processor and also applications. An external storage device is additionally usually much less complicated to include and support than interior storage since you don"t should physically open up a computer system to add capacity or change a drive.

Note: no all energetic or primary storage is internal, simply as no all outside and secondary storage is composed of a maker directly linked to a computer system -- because that example, the cloud or a warehouse array. Because that instance, in a tiered warehouse environment, main storage can consist of transaction or mission-critical applications data stored on HDDs and SSDs ~ above a central NAS or san that it is intended exceptionally high performance.

Security and data protection

Because security and data integrity space of paramount prestige to enterprises, institutions rarely deploy consumer-level, portable, outside storage devices. Best security techniques for enterprise-class exterior storage centers encompass data encryption and authentication.

Authentication protects data by ensuring outside storage resources are only accessible to authorized users and also trusted networks. Encryption secures data at rest on the external storage device itself and end-to-end together data is transmitted between external storage and also the computer system system or mobile an equipment accessing that information.

Data backup and archiving space tools because that protecting outside storage data. The is especially important to have actually a backup available when data in an outside storage device becomes corrupted as result of a software program or mechanically failure, virus, or outside storage device failure.

See more: A Restaurant That Creates A New Type Of Sandwich Is Using As A Method Of Competition.

Mirroring data to an additional storage an equipment via approaches like snapshots and also RAID is an additional useful way to protect data against catastrophic loss should something happen to an exterior storage an equipment and the data on it.

Related Termsgigabyte (GB)A gigabyte (GB) -- pronounced v two tough Gs -- is a unit of data storage capacity that is approximately equivalent come 1 billion ... SeecompletedefinitionMRAM (magnetoresistive random access memory)MRAM (magnetoresistive random access memory) is a method of save on computer data bits utilizing magnetic states instead of the electrical ... Seecompletedefinitionstorage volumeA warehouse volume is an i can identify unit the data storage. It have the right to be a removable hard disk, yet it walk not have to be a unit that... Seecompletedefinition